I've installed MM9 on a notebook running Vista. After some tinkering with the video options, the game finaly started and ran more or less smoothly (the alt-tab, alt-tab back after loading a saved game don't count).

However: when night time approaches, at exactly 5:01 PM game time, the screen turns pitch black! Nothing shown whatsoever of the 3D view, only the sidebars with the PCs/NPCs. At 5:59 AM next game day, everything returns to normal.

This is more than just irritating, the game actually becomes unplayable because in some quests you're required to act at night (such as the Mercenary quest).

Interestingly, if the slider 'Gamma Correction' under video options is in anything but the leftmost position, the game is always 100% black, not just at night.